1. It's dark. No sun = decent temperatures. In the Texas summers, everyone yearns for decent temps.
2. Traffic is at a bare minimum. I can run in the middle of the road if I like. On some streets I actually have to in order to save my ankles. At 5 a.m., I don't have to zig-zag back and forth to the sidewalk and the road for vehicles.
3. Mark one off the list. It's one less thing on my 'To-Do' list. Done, checked off, all before 6 o'clock in the morning and a cup of coffee.
4. Moonlight. I don't know what it is, there's just something awesome about running with the moon still up.